Ion-regulating Hybrid Electrolyte Interface for Long-life and Low N/P Ratio Lithium Metal Batteries

Practical lithium metal batteries (LMBs) require full and reversible utilization of limited metallic Li anodes at a solid/quasi-solid electrolyte condition.This puts forward to a fundamental challenging issue on how to create compatible interphases to regulate interfacial ionic transport and protect the reactive metal.Herein, to address these issues, a robust cellulosebased composite gel electrolyte (r-CCE) capable of stabilizing ion deposition is reported via compositing bacterial cellulose (BC) skeleton with Li6.4La3Zr1.4Ta0.6O12(LLZTO) particles.Benefiting from the decoupled segment structure of cellulose and additional ionic channels of LLZTO, r-CCE not only achieves high ionic conductivity (1.68 × 10 -3 S/cm) with a remarkable Li-ion transfer number (~0.92) and a wide window of electrochemical stability (~5.3 V), but also helps stabilize the Li anode.Utilizing ultrathin lithium metal anodes (15 μm), ultra-stable symmetric Li/Li cells that are armed with r-CCE demonstrate a highly stable plating/stripping process.Furthermore, a high areal capacity of ~4.2 mAh/cm 2 , and 100 cycles with obviously improved stability of the full Li metal batteries with n/p ratio of ~0.74 is achieved.